diff options
| author | Jarkko Nikula <jarkko.nikula@linux.intel.com> | 2015-01-23 12:35:55 +0300 |
|---|---|---|
| committer | Wolfram Sang <wsa@the-dreams.de> | 2015-01-26 18:58:26 +0300 |
| commit | 42ffd3907c1663441cd1bd4d1a575930b63a5964 (patch) | |
| tree | b50bac0f8565ef9bb3da2b593b494599a9451804 /drivers/i2c/busses/i2c-designware-core.c | |
| parent | c680eed5ccd4a1c99ee48cd41f4e5fdfad497dc2 (diff) | |
| download | linux-42ffd3907c1663441cd1bd4d1a575930b63a5964.tar.xz | |
i2c: designware: Do not calculate SCL timing parameters needlessly
Do SCL timing parameter calculation conditionally depending are custom
parameters provided since calculated values will get instantly overwritten
by provided parameters.
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c/busses/i2c-designware-core.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-designware-core.c | 45 |
1 files changed, 22 insertions, 23 deletions
diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c index fbb48fb138e7..6e25c010e690 100644 --- a/drivers/i2c/busses/i2c-designware-core.c +++ b/drivers/i2c/busses/i2c-designware-core.c @@ -320,40 +320,39 @@ int i2c_dw_init(struct dw_i2c_dev *dev) sda_falling_time = dev->sda_falling_time ?: 300; /* ns */ scl_falling_time = dev->scl_falling_time ?: 300; /* ns */ - /* Standard-mode */ - hcnt = i2c_dw_scl_hcnt(input_clock_khz, - 4000, /* tHD;STA = tHIGH = 4.0 us */ - sda_falling_time, - 0, /* 0: DW default, 1: Ideal */ - 0); /* No offset */ - lcnt = i2c_dw_scl_lcnt(input_clock_khz, - 4700, /* tLOW = 4.7 us */ - scl_falling_time, - 0); /* No offset */ - - /* Allow platforms to specify the ideal HCNT and LCNT values */ + /* Set SCL timing parameters for standard-mode */ if (dev->ss_hcnt && dev->ss_lcnt) { hcnt = dev->ss_hcnt; lcnt = dev->ss_lcnt; + } else { + hcnt = i2c_dw_scl_hcnt(input_clock_khz, + 4000, /* tHD;STA = tHIGH = 4.0 us */ + sda_falling_time, + 0, /* 0: DW default, 1: Ideal */ + 0); /* No offset */ + lcnt = i2c_dw_scl_lcnt(input_clock_khz, + 4700, /* tLOW = 4.7 us */ + scl_falling_time, + 0); /* No offset */ } dw_writel(dev, hcnt, DW_IC_SS_SCL_HCNT); dw_writel(dev, lcnt, DW_IC_SS_SCL_LCNT); dev_dbg(dev->dev, "Standard-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt); - /* Fast-mode */ - hcnt = i2c_dw_scl_hcnt(input_clock_khz, - 600, /* tHD;STA = tHIGH = 0.6 us */ - sda_falling_time, - 0, /* 0: DW default, 1: Ideal */ - 0); /* No offset */ - lcnt = i2c_dw_scl_lcnt(input_clock_khz, - 1300, /* tLOW = 1.3 us */ - scl_falling_time, - 0); /* No offset */ - + /* Set SCL timing parameters for fast-mode */ if (dev->fs_hcnt && dev->fs_lcnt) { hcnt = dev->fs_hcnt; lcnt = dev->fs_lcnt; + } else { + hcnt = i2c_dw_scl_hcnt(input_clock_khz, + 600, /* tHD;STA = tHIGH = 0.6 us */ + sda_falling_time, + 0, /* 0: DW default, 1: Ideal */ + 0); /* No offset */ + lcnt = i2c_dw_scl_lcnt(input_clock_khz, + 1300, /* tLOW = 1.3 us */ + scl_falling_time, + 0); /* No offset */ } dw_writel(dev, hcnt, DW_IC_FS_SCL_HCNT); dw_writel(dev, lcnt, DW_IC_FS_SCL_LCNT); |